In a power generation system such as a thermal power plant using a large amount of fossil fuel, an amine absorption method is employed as a method of removing and recovering carbon dioxide that is one of causes of global warming. However, in the amine absorption method, thermal energy obtained from a great amount of steam having low pressure (for example, approximately 0.3 MPa) is required to regenerate an absorption liquid having absorbed carbon dioxide.
In order to compensate this thermal energy, there is proposed a method of joining condensate, which is branched from a turbine condensate system, to a deaerator after performing heat exchanging between the amount of heat of absorbed carbon dioxide and the amount of heat generated by compressing carbon dioxide to high pressure (for example, approximately 8 MPa) that is suitable for injecting carbon dioxide into the ground.
However, there has been a problem in that the amount of condensate is not enough to recover the total amount of heat of carbon dioxide. As a result, the amount of condensate flowing in a low-pressure heater is reduced, the amount of gas extracted from a turbine is reduced, and the heat dumped to a steam condenser is increased, so that the effect of a regeneration cycle in the related art is decreased. For this reason, there has been a problem in that the output of the turbine is not particularly increased by the amount of recovered heat.
Further, in the injection of the recovered carbon dioxide into the ground, carbon dioxide needs to be compressed to be a high pressure. However, in order to ensure the power source of such a compression, the output of the power plant is excessively and inevitably decreased.